[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging
From: |
Alexander Graf |
Subject: |
Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging |
Date: |
Tue, 24 Aug 2010 15:46:14 +0200 |
User-agent: |
Thunderbird 2.0.0.23 (X11/20090817) |
Daniel P. Berrange wrote:
> On Tue, Aug 24, 2010 at 03:40:25PM +0200, Alexander Graf wrote:
>
>> Daniel P. Berrange wrote:
>>
>>> On Tue, Aug 24, 2010 at 12:45:19PM +0200, Alexander Graf wrote:
>>>
>>>>> The key is that you should use if=none for all cases. Here are two
>>>>> examples of how libvirt does it currently:
>>>>>
>>>>> VirtIO:
>>>>>
>>>>> drive_add dummy
>>>>> file=/var/lib/libvirt/images/data.img,if=none,id=drive-virtio-disk1,format=raw
>>>>> device_add
>>>>> virtio-blk-pci,bus=pci.0,addr=0x0,drive=drive-virtio-disk1,id=virtio-disk1'
>>>>>
>>>>> SCSI:
>>>>>
>>>>> drive_add dummy
>>>>> file=/var/lib/libvirt/images/data.img,if=none,id=drive-scsi0-0-1,format=raw'
>>>>> device_add
>>>>> scsi-disk,bus=scsi0.0,scsi-id=1,drive=drive-scsi0-0-1,id=scsi0-0-1
>>>>>
>>>>> The 'dummy' value there can be absolutely anything you want.
>>>>> It is totaly ignored when QEMU sees if=none in 2nd arg.
>>>>>
>>>>>
>>>>>
>>>> I'd be all for removing the pci-hotplug.c version of drive_add then. But
>>>> I think the IF_SCSI option there is to append a drive to an existing
>>>> SCSI bus, no?
>>>>
>>>>
>>> Actually this SCSI example I give above is appending a drive to an existing
>>> bus (scsi0), in slot 1 (scsi-id=1). To best of my knowledge there is no
>>> remaining use case that requires use of IF_SCSI, IF_IDE, etc. The IF_NONE
>>> approach can cope with all, modulo bugs that appear periodically with code
>>> that mistakenly checks for a particular IF_XXX constant.
>>>
>>> If you wanted to also create a new SCSI bus, before creating the drive on
>>> it, you'd need to run three commands in total:
>>>
>>> device_add lsi,id=scsi0,bus=pci.0,addr=0x7
>>> drive_add dummy
>>> file=/var/lib/libvirt/images/data.img,if=none,id=drive-scsi0-0-1,format=raw
>>> device_add
>>> scsi-disk,bus=scsi0.0,scsi-id=1,drive=drive-scsi0-0-1,id=scsi0-0-1
>>>
>>>
>> Nice - so we can just deprecate if=!none?
>>
>
> In theory yes, but its not nice to tell users to switch everything over to
> use if=none, if we're going to deprecate that too in the next release when
> blockdev appears. Might as well just deprecate entire of drive_add/-drive
> at once.
>
I guess I still fail to see the reason for blockdev when we force
drive_add to if=none...
Alex
- Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging, (continued)
Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging, Daniel P. Berrange, 2010/08/24
- Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging, Alexander Graf, 2010/08/24
- Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging, Daniel P. Berrange, 2010/08/24
- Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging, Alexander Graf, 2010/08/24
- Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging, Daniel P. Berrange, 2010/08/24
- Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging,
Alexander Graf <=
- Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging, Daniel P. Berrange, 2010/08/24
- Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging, Markus Armbruster, 2010/08/27
Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging, Anthony Liguori, 2010/08/24
Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging, Alexander Graf, 2010/08/24
Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging, Markus Armbruster, 2010/08/27
[Qemu-devel] [PATCH 1/5] [S390] Add hotplug support, Alexander Graf, 2010/08/23